The invention relates to a machining tool with a detachable head.
Machining tools are composed of a support that is slender overall wherein one of the two ends, called the active end, holds at least one cutting blade, and the other end, called the anchoring end, is adapted for being coupled with a tool holder such as a chuck of a machine tool.
Machining tool is understood to mean reamers that specifically make it possible to produce semi-finished surfaces, rather than boring tools or drills.
Drills are tools that form a roughly cylindrical cavity, while a reamer makes it possible to have a boring having the desired dimensions with substantial precision.
There are many existing coupling means for these reamers, and hence if one is using a set of machines from various sources, it is necessary to multiply the number of machining tools.
To obviate this problem, it is known to produce the machining tool in two parts comprising a head detachably mounted on a body having, in a rear part, means for coupling with a type of machine tool.
In order to ensure this detachability, means for fastening the head to the body are provided.
A screw system was initially used, and more precisely, one of the two pieces has a threaded hole into which a screw rod held by the other piece is inserted.
Angularly positioning the head relative to the axis of rotation of the body is nearly impossible because of the tolerances of the threads.
In place of this fastening system, is known to fasten the head by means of a screw passing axially through the rear part of the body of the tool and to mount the head so that it rotates around the axis of the rear part by means of two screws disposed radially in one of the two pieces, i.e., the rear part or the head, whose ends rest against two flat surfaces of the other piece.
A mounting of this type, as well as the preceding mounting, do not make it possible to convey a lubrication and/or cooling fluid through the tool.
In the boring field, there is a known fastening device (U.S. Pat. No. 1.422.058), which consists of forming on the back of a drill an annular groove into which a pivoting hook anchors laterally.
A sleeve covers the assembly locally so as to form a coupling.
A disposition of this type cannot be adapted to a reamer, wherein the rear part of the tool must have dimensions smaller than the diameter of the head.
The position of the anchoring of the hook also causes the tool to rock.
Moreover, it is impossible to direct a cooling fluid through the body of the tool.
The object of the invention is specifically to eliminate this drawback.
To this end, the subject of the invention is a machining tool comprising:
a head holding at least one cutting blade,
a slender body and
means for detachably fastening the head to the slender body,
this device being characterized in that:
the head comprises, in the rear part, a rotating cylinder centered on the axis of rotation of the tool, this rotating cylinder having, in its rear end, a clevis provided with a so-called catch pin and in its so-called front end, at least one lug projecting from the cylindrical surface,
the slender body has:
opening into its side facing the head, a boring for housing the aforementioned rotating cylinder and a hook mounted on a pivot pin, which hook is movable by a control means between a so-called locked position in which said hook is engaged with the so-called catch pin of the head and a so-called released position that makes it possible to insert and remove the cylinder from the boring.
in the cylindrical wall delimiting the boring, at least one notch for receiving the aforementioned lug.